Weekend Project Thread

Alonzo

Alonzo

Member
Got some time off for the holiday, so I thought I'd document a weekend project.
Start with a Single (45) schematic and parts list, add a fairly full parts bin and you get a junk'd full breadboard that HUMMS.



Today the little brown truck arrived and brought in a top plate and base from the good elves north of me.


Now how to squeeze this into this....over the weekend



Also have to deal with the hummmmmmm......

Going bare on the chassis, can't decide on a good color.  The base will be varnished with some gloss polyu I have on hand.

Wish me luck; I'll be adding notes and pictures to show the progress.
Alonzo
 

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I could do that ... only my wires would originate and end up at random points and it wouldnt work  ;D    I envy you guys who understand this stuff enough to be able to put something together from old parts or scratch and make it work.  I have fixed a few vintage tube amps and such that didnt work or didnt work right but never considered that it was anything much more than luck.  Plus I had online help with schematics, parts and general advice.  I guess I shouldnt complain as most people couldnt even do that and I still got the satisfaction of getting it working and enjoying afterward.  Im definitely more of a kit guy, not a from scratch builder.  Im just an all around jack of all trades, master of none ... except maybe one, I was good at my job  ;)

Happy 4th and please update, I enjoy seeing this stuff.
 
Alonzo,

You always crack me up with your use of things unintended for DIY.  The outlet cover plate with hole shrinkers is what I mean in this case.

It looks like you will need a shoe horn to get all that into the FP III chassis/base.  Maybe some Crisco?
 
Never thought of using an outlet cover plate as a tube mount, very creative! Almost looks like something Decware would make.


Cheers,
Shawn
 
OOOOO  Decware. I have dealt with some of their stuff. Some I liked, some I sold. But honestly, I still miss a pair of mono amps. that they made many years ago. Good looking, solidly built, and I haven't had that kind of luck since. I will, however, finally be diving into a simple Quickie kit. I have no doubt that it will sound better than expected. Simple things usually do.  Now, where did I put my stash of brass outlet plates?
 
Hope everyone had a safe and Happy Independence Day!!!

Didn't get much done, too much of the "adult lemonade" and burgers to attempt anything more than using a screwdriver.  I have the stereomour chassis and thought I'd somewhat mimic the layout but after putting parts in, saw that it wouldn't work so most of the tag boards you see in the picture are being removed tonight.  Since I'm making this up as I go, I'm going to build out the power supply then one channel, hopefully working out the layout bugs and adding the second side. 

Laudanum, I'm a kit guy myself.  I prefer them to scratch builds but sometimes the money doesn't work out for buying a kit so you do what you can.  I'll be leaning heavily on the community here for help, I try to keep a simple build, not get too over my head but learn something new each time.  And I subscribe to Grainger's motto "If it sounds good to you then eff everybody else" (or something like that  ;D.)  Whenever I think different I visit an audio retailer down the street, listen to his high end gear and smile, I"m more satisfied in building it myself and having it sound good and using the extra money on a good steak, cigar and single malt.
I join you in the JOAT club, the Navy made me that way.

Yesterday's progress pics attached.  So far so good but this isn't the hard part...
 

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Alonzo ... JOAT has served me well with lots of things over the years but especially because it has kept the wife happy with those honey-do's and saved a boat load of money in the process.  ;)
 
Lost an update somewhere in the ether...

So far not much progress, but I have a great reason why.  Recieved my 6th grandchild, Bennet Elias Bradford into the fold so I'm having a ton of fun with the new baby to visit.

I did some cleanup and mounting of parts yesterday, got the power supply transformer on some offsets, added the chokes (4) and output transformers,etc.  Now I have to plan out the ground plane and the layout for a CLCRC filter on the tag board.

Anyone have experience with Sprague Atom capacitors, I have 2 and wonder is it worth the effort to try to fit them in the power supply?  Will have some time next week, hope to get this to power testing by Friday.
 

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Alonzo,

Congratulations on both the birth of a grandchild and the impending birth of the amp.

Sometimes life just gets in the way of builds.
 
Losing post somewhere when the pictures are too big.  Here's the latest on the project, 45 amp in a Stereomour dress.  Got alot finished but it's not complete, theres some imbalance between the channels and I need to track down and eliminate some hum.

Some things left to do:  replace the chokes with BCP-15's, new power resistors of the correct value, possibly a fan underneath (this amp runs hot, touchable but definitely warm), oil caps to replace the big Sprague ones in the power supply, clean up the chassis some and find some vintage knobs, maybe upgrade the Solen's to Obliggatos, maybe replace the power transformer, maybe a Nixie tube indicator or as a meter.

It has about 40 hours on it, I'm reserving sonic judgement until it's over 100.

Here's some pics, please forgive the wiring mess, I starts out neat in my head then ends up like my desk...
 

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Alonzo,

Nice work.  Very Bottlehead.

In the FAQ Thread in my corner there are instructions on how to post pictures from a hosting site.

Can you put the old late chokes into the power supply like in the old Paramour upgrade?  I'd hate to waste good iron that can improve the power supply.  It looks like there is iron below the plate already.
 
Thanks, it's got a C-7X choke in the power supply.  It's a CLCRC, 100uf/10Hy/100uf/1.5K/82uf, and there's a .01/630v across the incoming power (don't know if it does any good, had an extra from a Foreplay mod to use).  The plate chokes and outputs are under the top plate, I've ordered new chokes from Mike, just waiting for them to show up.  Going to add a right angle power cord as soon as that comes in also.
 
Alonzo,

that standard film cap across the incoming line is potentially dangerous -- typical coupling caps are not rated for AC power line use.  If you're going to do that you should find some X1 rated caps  These have a guaranteed failure mode, unlike a standard cap which does not.

Are you using the exo-45s you got from me?

-- Jim
 
coming in late on this but I also have aspirations to read a schematic and build a kit from scratch! I find that very cool. I give credit to Bottlehead for the intro. Before that I didnt know a triode from pentode. I know it will probably happen at some stage, but for now, I'm a practical audiophile, and if it aint broken I'm not fixing it!
 
Jim, what's an X1 rating?  I looked up the data sheet for the cap I'm using and it states the cap is good up to 250v AC at 60Hz.  It's a Vishay MKP 1840.  Yes, I'm using the EXO-45 I got from you, they aren't broken in yet but will be soon.

While I was under checking the cap, swapped out the Sprague and changed out some resistors.  Trying to decide whether to connect the heater center taps to ground, if it'll make a difference in the hum.

Grainger, thanks for the link.  I ordered a bottlehead cord kit to try.

New pics...
 

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Alonzo,

OOoooo  Lots of caps and iron.  Makes for a sweet sounding amp.

Do I see a FP 2 in the background, upper left, in the background of the second picture?
 
Grainger,
Good eye!! That Foreplay wasn't getting any use since I put Quickies in my system.  It is now the sacrificial lamb for an idea for a Foreplay with switchable inputs and outputs, I want something I can switch between my 3 sources and 3 amps and 3 sets of speakers plus a sub to each when needed.  I used the Foreplay chassis to get a copper top made, the base to house one of my Quickies.  So far that's as far as I've got, I keep thinking adding tubes to a switch box would be overkill since I already have preamps in the setup.  But I've got to do something with all the 12AU7's I have!!!!!
 
Hey Grainger,
What do you know about Grid chokes?  I did a search but the info was confusing, cycling between different amps, different values, etc. so I thought I'd ask.  Did you ever put grid chokes on your paramours?  If so where?  What kind of improvement did you get?
Thanks!!!
 
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